Tunable wavelength filter using nano-sized droplets of liquid crystal

Long-wavelength vertical-cavity surface-emitting laser using an electro-optic index modulator with 10nm tuning range

“…3 shows the laser peak wavelength calculated from the quadratic dependency of the refractive index with the electric field. In agreement with a previous work, 6 the simulation based on the transfer matrix formalism and this relationship provide a good approximation of the wavelength shift in the weak electrical field limit. As illustrated in Fig.…”

“…Recently, the use of nano-polymer dispersed liquid crystal (PDLC) for optical applications has shown potential for polarization independence and fast tuning speed. 6,7 In this letter, we present an original use of such an electro-optic material to provide tunability of a long wavelength VCSEL. The device using a nano-PDLC material as an electro-optic index modulator is robust and easy to fabricate.…”

“…A spin-coated method is under study to improve the UV irradiation of the polymer in order to obtain smaller optical losses for the electro-optic layer. 6 Others optimizations can be carried out like the use of a more efficient semiconductor DBR for the bottom mirror. Larger tuning ranges could be obtained with larger birefringence LCs 13 …”

Electrical tunable Fabry–Perot interferometer using a poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) terpolymer

“…Due to the opposite sign of the field-induced strain and the refractive index change from the electro-optic effect, the FPI using a terpolymer film directly as the cavity of the etalon shows a smaller tunability (0.78% under 100 V/µm Fabry-Perot interferometer (FPI) has been used widely in high resolution spectroscopy, as electro-optical (E-O) modulators and optical filters. [1][2][3][4][5][6][7] Recently, a great deal of effort has been devoted to developing high performance tunable FPI, which can be operated by the change of refractive index of etalons or the space between two reflective mirrors with the external stimulus, such as electric, magnetic field, or temperature change. [1][2][3][4][5][6][7] One key parameter in selecting an active material or device for tunable FPI is the large tunable range.…”

“…[1][2][3][4][5][6][7] Recently, a great deal of effort has been devoted to developing high performance tunable FPI, which can be operated by the change of refractive index of etalons or the space between two reflective mirrors with the external stimulus, such as electric, magnetic field, or temperature change. [1][2][3][4][5][6][7] One key parameter in selecting an active material or device for tunable FPI is the large tunable range. Therefore, materials with large E-O effect or large electric field-induced strain are very attractive for electric tunable FPIs.…”